The Chilean played the full 90 minutes of the fixture, in which the Red Devils stormed into a 1-0 lead through Paul Pogba.

Arsenal pegged back their Premier league rivals after the break, when former United midfielder - who swapped places with Sanchez in January - Henrikh Mkhitaryan equalised five minutes into the second half.

But it was the home side who had the final say at Old Trafford when Marouane Fellaini bagged a 90th minute winner to secure all three points.

(Image: REUTERS)

After the game Sanchez took to social media to post a picture of himself in action against his former team.

Alongside the image he wrote: "Happy for the win.

Marouane Fellaini bagged a 90th minute winner to secure the points for Man United (Image: PA)

"But for next season, if we want to fight for the Premier League and the champions and everything that comes, we must keep improving because we are the MANCHESTER UNITED. ALL TOGETHER FAMILY."

Manchester United fans were quick to heap praise on the Chilean, while Arsenal supporters on Instagram were unsurprisingly disappointed.

Sanchez embraced Arsene Wenger before the start of the game

Arsene Wenger, who will stand down as Arsenal boss at the end of the season after 22 years in charge, was presented with a silver vase on the pitch on Saturday.

After the game he said: "It was very nice and classy. I enjoyed it. I have come here for a long, long time. Next year, someone else will be in the dug-out and it will be a hostile environment again."